serial: lpuart: add i.MX7ULP support

Add i.MX7ULP support.
The buadrate calculation on i.MX7ULP is different,so add a new setbrg
function for i.MX7ULP.
Add a enum lpuart_devtype for runtime check for different platforms.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Cc: York Sun <york.sun@nxp.com>
Cc: Shaohui Xie <Shaohui.Xie@nxp.com>
Cc: Alison Wang <b18965@freescale.com>
diff --git a/include/fsl_lpuart.h b/include/fsl_lpuart.h
new file mode 100644
index 0000000..4643ee7
--- /dev/null
+++ b/include/fsl_lpuart.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2016 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ *
+ */
+
+#ifdef CONFIG_ARCH_MX7ULP
+struct lpuart_fsl_reg32 {
+	u32 verid;
+	u32 param;
+	u32 global;
+	u32 pincfg;
+	u32 baud;
+	u32 stat;
+	u32 ctrl;
+	u32 data;
+	u32 match;
+	u32 modir;
+	u32 fifo;
+	u32 water;
+};
+#else
+struct lpuart_fsl_reg32 {
+	u32 baud;
+	u32 stat;
+	u32 ctrl;
+	u32 data;
+	u32 match;
+	u32 modir;
+	u32 fifo;
+	u32 water;
+};
+#endif
+
+struct lpuart_fsl {
+	u8 ubdh;
+	u8 ubdl;
+	u8 uc1;
+	u8 uc2;
+	u8 us1;
+	u8 us2;
+	u8 uc3;
+	u8 ud;
+	u8 uma1;
+	u8 uma2;
+	u8 uc4;
+	u8 uc5;
+	u8 ued;
+	u8 umodem;
+	u8 uir;
+	u8 reserved;
+	u8 upfifo;
+	u8 ucfifo;
+	u8 usfifo;
+	u8 utwfifo;
+	u8 utcfifo;
+	u8 urwfifo;
+	u8 urcfifo;
+	u8 rsvd[28];
+};
+
+/* Used on i.MX7ULP */
+#define LPUART_BAUD_BOTHEDGE_MASK	(0x20000)
+#define LPUART_BAUD_OSR_MASK		(0x1F000000)
+#define LPUART_BAUD_OSR_SHIFT		(24)
+#define LPUART_BAUD_OSR(x)		((((uint32_t)(x)) << 24) & 0x1F000000)
+#define LPUART_BAUD_SBR_MASK		(0x1FFF)
+#define LPUART_BAUD_SBR_SHIFT		(0U)
+#define LPUART_BAUD_SBR(x)		(((uint32_t)(x)) & 0x1FFF)
+#define LPUART_BAUD_M10_MASK		(0x20000000U)
+#define LPUART_BAUD_SBNS_MASK		(0x2000U)